U.S. patent application number 10/042216 was filed with the patent office on 2002-09-05 for soft polyurethane foam.
Invention is credited to Katsumata, Yoshihiro, Kinoshita, Hideya.
Application Number | 20020123536 10/042216 |
Document ID | / |
Family ID | 26409596 |
Filed Date | 2002-09-05 |
United States Patent
Application |
20020123536 |
Kind Code |
A1 |
Kinoshita, Hideya ; et
al. |
September 5, 2002 |
Soft polyurethane foam
Abstract
A soft polyurethane foam obtained by foaming a polyurethane raw
material including a phenolic antioxidant selected from
3,9-bis[2-{3-(3-t-butyl-4-- hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxa- pyro [5,5]
undecane and/or 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate in an amount of
0.05-2.0 parts by weight, a benzotriazole type UV absorbing agent
in an amount of 0.1-3.0 parts by weight, and a phosphorus type
antioxidant in an amount of 0.5-6.0 parts by weight for 100 parts
by weight of a polyol component. Color migration and discoloration
of a soft polyurethane foam are prevented.
Inventors: |
Kinoshita, Hideya;
(Kanagawa, JP) ; Katsumata, Yoshihiro; (Kanagawa,
JP) |
Correspondence
Address: |
STAAS & HALSEY LLP
700 11TH STREET, NW
SUITE 500
WASHINGTON
DC
20001
US
|
Family ID: |
26409596 |
Appl. No.: |
10/042216 |
Filed: |
January 11, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10042216 |
Jan 11, 2002 |
|
|
|
09267673 |
Mar 15, 1999 |
|
|
|
Current U.S.
Class: |
521/88 |
Current CPC
Class: |
C08G 18/4833 20130101;
C08J 2375/04 20130101; C08J 9/0023 20130101; C08G 2110/0008
20210101 |
Class at
Publication: |
521/88 |
International
Class: |
C08K 003/00; C08J
009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 1998 |
JP |
H10-68370 |
Claims
What is claimed is:
1. A polyurethane foam obtained by foaming a polyurethane raw
material comprising: a polyol component; a phenolic antioxidant
selected from 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimet- hylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane and 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate in an amount of
0.05-2.0 parts by weight for 100 parts by weight of the polyol
component; a benzotriazole UV absorbing agent in an amount of
0.1-3.0 parts by weight for 100 parts by weight of the polyol
component; and a phosphorous antioxidant in an amount of 0.5-6.0
parts by weight for 100 parts by weight of the polyol component,
wherein the polyurethane raw material is substantially free of
dibutyl cresol.
2. The polyurethane foam according to claim 1, wherein the
polyurethane raw material further comprises, in relation to 100
parts by weight of the polyol component, an isocyanate component
(10-80 parts by weight), a catalyst (0.01-2.0 parts by weight), a
foaming agent (1.0-25.0 parts by weight), and a foam stabilizer
(0.01-3.0 parts by weight).
3. The polyurethane foam according to claim 2, wherein the polyol
component has a number average molecular weight of 2500-5000, and
an OH value of 40-60.
4. The polyurethane foam according to claim 2, wherein the
isocyanate component comprises an organic polyisocyanate containing
two or more isocyanate groups in one molecule and being selected
from aliphatic polyisocyanate compounds, aromatic polyisocyanate
compounds or modified products thereof.
5. The polyurethane foam according to claim 1, wherein the phenolic
antioxidant is selected to be only
3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-me- thylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro {5,5}
undecane.
6. The polyurethane foam according to claim 1, wherein the
benzotriazole UV absorbing agent is in the amount of 0.1-2.0 parts
by weight for 100 parts by weight of the polyol component.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of,
and claims the benefit under 35 U.S.C. .sctn.120 of, pending U.S.
Ser. No. 09/267,673, entitled "Soft Polyurethane Foam", filed on
Mar. 15,1999.
[0002] This application also claims the benefit under 35 U.S.C.
Section 119 of Japanese Patent Application Serial No. H10-68370,
filed Mar. 18,1998, which is hereby incorporated by reference in
its entirety into this application.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a soft polyurethane foam.
More particularly, the present invention relates to a soft
polyurethane foam which does not cause discoloration or color
migration, and which is useful for a pad material for
clothing-related uses such as a brassiere pad, shoulder pad, and
hanger pad, and the like.
[0005] 2. Description of the Related Art
[0006] Soft polyurethane foams have good cushioning properties, and
unlike cotton, they do not loose their elasticity and have a soft
and good feel even after being used for a long time or repeatedly;
therefore they have been widely used for a pad material for
clothing-related uses such as a brassiere pad, shoulder pad, and
hanger pad, and the like.
[0007] The conventional soft polyurethane foam having been produced
from a polyol raw material containing BHT (dibutyl cresol) as an
antioxidant, involves problems arising from the BHT, such as
discoloration of the foam itself, or color migration (the cloth in
contact with the soft polyurethane foam is stained). That means,
when a raw material composition containing BHT is foamed to produce
polyurethane, BHT remains in the foam after the foaming step, and
reacts with nitrogen oxides contained in the atmosphere to yellow
the urethane foam. Since BHT is sublimable, it evaporates and
adheres to cloth nearby to discolor the cloth likewise.
[0008] The soft polyurethane foam discolors by the effects of
ultraviolet rays as well.
[0009] Such discoloration and color migration of the foam present a
significant defect of a soft polyurethane foam for clothing-related
uses.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to solve the
above-mentioned conventional problems and to provide a soft
polyurethane foam wherein the discoloration thereof and the color
migration therefrom are prevented.
[0011] The soft polyurethane foam according to the present
invention is produced by foaming a polyurethane raw material which
satisfies one or more, preferably two or more, more preferably all
of the following conditions (i)-(iii), and which is substantially
free from BHT. (i) the polyurethane raw material includes a
phenolic antioxidant selected from
3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimet- hylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane and/or 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate in an amount of
0.05-2.0 parts by weight for 100 parts by weight of the polyol
component; (ii) the polyurethane raw material includes a
benzotriazole type UV absorbing agent in an amount of 0.1-3.0 parts
by weight for 100 parts by weight of the polyol component; and
(iii) the polyurethane raw material includes a phosphorus type
antioxidant in an amount of 0.5-6.0 parts by weight for 100 parts
by weight of the polyol component.
[0012] As noted above, the color migration of the soft conventional
polyurethane foam occurs from sublimation and adhesion of BHT to
cloth. According to the present invention, the antioxidant used in
the raw material is changed from BHT to
3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methy- lphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane and/or 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphen- yl) propionate to prevent the
color migration. That is, the foam is substantially free of
BHT.
[0013] The macromolecular phenolic antioxidant is preferably
3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimet- hylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane.
[0014] As the yellowing of the soft polyurethane foam is largely
affected by UV, according to the present invention, the UV
absorbing agent is added to prevent the discoloration.
[0015] In addition, the discoloration of the soft polyurethane foam
with NO.sub.x and the discoloration of the soft polyurethane foam
during hot press are effectively prevented by the use of the
phosphorus type antioxidant.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Embodiments of the present invention will be explained in
detail.
[0017] Each of the weight values of BHT, 3,9-bis
[2-{3-(3-t-butyl-4-hydrox- y-5-methylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane and 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyp- henyl) propionate described herein
is calculated based on the atomic weights of C-12, H-1, and
O-12.]
[0018] According to the present invention, color migration due to
the evaporation of the antioxidant is prevented by blending a
phenolic antioxidant selected from
3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylpheny-
l)propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro[5,5]
undecane having a molecular weight of 741 and/or
2,2'-thio-diethylene bis [3-(3,5-di-t-butyl-4-hydroxyphenyl)
propionate having a molecular weight of 642.9 with a polyurethane
raw material, therefore the polyurethane raw material becomes
substantially free from BHT. These phenolic antioxidants can be
used separately or in combination.
[0019] A commercially-available example of
3,9-bis[2-{3-(3-t-butyl-4-hydro- xy-5-methylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane is "AO80" and a commercially-available example of
2,2'-thio-diethylene bis [3-(3,5-di-t-butyl-4-hydroxyphenyl)
propionate is "AO75", both of which are available from Asahi Denka
Kogyo K.K.
[0020] When the phenolic antioxidant selected from
3,9-bis[2-{3-(3-t-butyl- -4-hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetra- oxapyro [5,5]
undecane and 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate is contained in an
amount of less than 0.05 parts by weight for 100 parts by weight of
the polyol component in the polyurethane raw material, the
oxidation inhibition performance is weak, and the stability of the
raw material itself is lowered. When the amount exceeds 2.0 parts
by weight, however, the appearance of the obtained soft
polyurethane foam is inferior and the raw material cost is
increased. Accordingly, the amount of the antioxidant is preferably
0.05-2.0 parts by weight for 100 parts by weight of the polyol
component in the polyurethane raw material.
[0021] A benzotriazole type UV absorbing agent is mixed in the
polyurethane raw material to prevent the yellowing of the foam by
UV. Commercially-available examples of the benzotriazole type UV
absorbing agent are "T-213" available from Ciba-Geigy Ltd., and
"LA-31" available from Asahi Denka Kogyo K.K., and the like. Of
course, similar UV absorbing agents can be used.
[0022] When the amount of the benzotriazole type UV absorbing agent
contained is less than 0.1 parts by weight for 100 parts by weight
of the polyol component in the polyurethane raw material,
sufficient effects can not be derived from the addition, and when
the amount exceeds 3.0 parts by weight, the appearance of the
obtained soft polyurethane foam is inferior and the raw material
cost is increased. Accordingly the amount of the benzotriazole type
UV absorbing agent used is preferably 0.1-3.0 parts by weight for
100 parts by weight of the polyol component in the polyurethane raw
material.
[0023] Conventional discoloration of the foam itself caused by NOx
or by hot press can be prevented by blending a phosphorus type
antioxidant with the polyurethane raw material.
Commercially-available examples of the phosphorus type antioxidant
are "3010" and "1178", and the like, available from Adeka Co.,
Ltd.
[0024] When the amount of the phosphorus type antioxidant is less
than 0.5 parts by weight for 100 parts by weight of the polyol
component in the polyurethane raw material, sufficient effects
cannot be derived from the addition, and when the amount exceeds
6.0 parts by weight, the appearance of the resulting soft
polyurethane foam is inferior and the raw material cost is
increased. Therefore, the amount of the phosphorus type antioxidant
blended is preferably 0.5-6.0 parts by weight for 100 parts by
weight of the polyol component in the polyurethane raw
material.
[0025] It is preferable that the polyurethane raw material be
substantially free from BHT and contain the phenolic antioxidant
selected from 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane and 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate in an amount of
0.05-2.0 parts by weight, a benzotriazole type UV absorbing agent
in an amount of 0.05-1.0 parts by weight, and the phosphorus type
antioxidant in an amount of 0.5-6.0 parts by weight, for 100 parts
by weight of the polyol component, in order to prevent both the
color migration and the discoloration of the foam itself.
[0026] A soft polyurethane foam of the present invention can be
produced from an ordinary raw material, according to a conventional
process such as the following method, except that the polyurethane
raw material contains the predetermined antioxidants, and the like,
as described above. The NCO index of the raw material is preferably
90-120.
[0027] <Polyurethane raw material composition (parts by
weight)>
[0028] Polyol component: 100 parts by weight
[0029] Isocyanate component: 10-80 parts by weight
[0030] Catalyst: 0.01-2.0 parts by weight
[0031] Foaming agent: 1.0-25.0 parts by weight
[0032] Foam stabilizer: 0.1-3.0 parts by weight
[0033] All the parts by weight of the isocyante, catalyst and
foaming agent and stabilizers are relative to the 100 parts by
weight of the polyol component.
[0034] As for the polyol component, there is no particular
restriction, however, those having a number average molecular
weight of 2500-5000, an OH value of 40-60 are preferably used. A
commercially-available example is GP300 from Dow Polyurethane Co.,
Ltd.
[0035] As for the isocyanate component, there is no particular
restriction, however, an organic polyisocyanate having two or more
isocyanate groups in one molecule, including aliphatic and aromatic
polyisocyanate compounds and their modified products is used.
Examples of the aliphatic polyisocyanate include hexamethylene
diisocyanate, isophorone diisocyanate, dicyclohexylmethane
diisocyanate, methylcyclohexane diisocyanate and the like. Examples
of the aromatic polyisocyanate include toluene diisocyanate,
diphenylmethane diisocyanate, polymeric disphenylmethane
diisocyanate and the like. As their modified products, carbodiimide
modified substances and prepolymer modified substances can be used.
Preferable polyisocyanates according to the present invention
include aromatic polyisocyanates or aromatic polyisocyanate
modified products, in particular, diphenylmethane isocyanate,
toluene diisocyanate, diphenylmethane diisocyanate and the like are
preferred.
[0036] The foam stabilizer may be silicone oil, or the like.
[0037] As for the foaming agent, any foaming agent which can be
used for production of a polyurethane foam can be used. Examples
thereof include methylene chloride, flon type compounds such as
trichlorofluoromethane and dichlorodifluoromethane, as a low
boiling point inactive solvent, water, acid amides and nitroalkanes
and the like as a substance which generates a gas by liquefied
carbon dioxide gas reaction, sodium hydrogen carbonate, ammonium
carbonate and the like as a substance which generates a gas by heat
decomposition. Among these, methylene chloride, water and the like
are preferred as the foaming agent.
[0038] As a catalyst, any catalyst which can be used for an
ordinary urethane foam production can be used. Examples thereof
include tin type catalysts such as dibutyltin dilaurate, stannous
octoate, and tertiary amines such as triethylamine and tetramethyl
hexamethylenediamine,
[0039] The polyurethane foam of the present invention may contain a
surfactant, a flame retardant, or other assistants, if necessary.
As a surfactant, a silicone type surfactant can be usually
employed. As a flame retardant, an organic powder such as urea and
thiourea or an inorganic powder such as a metal hydroxide and
antimony trioxide can be used in addition to the conventionally
known flame retardant such as tris (2-chloroethyl) phosphate, tris
(2,3-dibromopropyl) phosphate, and the like.
[0040] Examples of other assistants include a coloring powder such
as a pigment and dye, a powder such as talc, graphite, glass short
fiber, and other inorganic fillers, and an organic solvent.
EXAMPLES AND COMPARATIVE EXAMPLES
[0041] Without further elaboration, it is believed that one skilled
in the art, using the preceding description, can utilize the
present invention to its fullest extent. The following embodiments
are, therefore, to be construed as merely illustrative, and not
limitative in any way whatsoever, of the remainder of the
disclosure.
[0042] The present invention is further illustrated by the
following Examples and Comparative Examples.
Examples 1-7, Comparative Examples 1-10
[0043] Polyurethane raw materials having the compositions shown in
Table 1 were foamed at 25.degree. C. according to an ordinary
process to produce soft polyurethane foams. The color migration,
discoloration by UV and discoloration by NOx of the produced soft
polyurethane foams were examined by the following methods and the
results are shown in Table 1.
[0044] <Color Migration>
[0045] A urethane foam was wrapped in a polyester cloth and allowed
to stand at 50.degree. C. for 48 hours, then the polyester cloth
was exposed to 50 ppm NO.sub.x for 2 hours, and allowed to stand at
50.degree. C. for 30 days. Then Yl value (based on a white plate)
of the polyester cloth was measured by "ZE2000" available from
Nippon Denshoku Sha K.K. The larger the Yl value, the bigger the
degree of discoloration.
[0046] <Discoloration by UV>
[0047] A polyurethane foam was irradiated with UV for 9 hours using
one carbon arc and the Yl value based on the white plate was
determined by "ZE2000" available from Nippon Denshoku Sha K.K.
[0048] <Discoloration by NO.sub.x>
[0049] A polyurethane foam was allowed to stand in an atmosphere
containing NO.sub.x of 500 ppm for 2 hours then the Yl value based
on the white plate was measured by "ZE2000" available from Nippon
Denshoku Sha K.K.
1 Examples 1 2 3 4 5 6 7 Polyurethane Polyol *1 100 100 100 100 100
100 foam raw Antioxidant *2 0.30 0.30 0.30 0.30 0.30 0.30 material
Antioxidant *11 0.30 compositions Antioxidant *3 (wt part)
Antioxidant *4 5.0 2.0 5.0 2.0 Ethanox 330 Cyanox 2246 Irganox 1010
Irganox 1076 UV absorbing agent *5 2.0 1.0 2.0 1.0 1.0 Water 3.6
3.6 3.6 3.6 3.6 3.6 3.6 Amine catalyst *6 0.25 0.25 0.25 0.25 0.25
0.25 0.25 Amine catalyst *7 0.25 0.25 0.25 0.25 0.25 0.25 0.25 Foam
stabilizer *8 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Tin catalyst *9 0.5 0.5
0.5 0.5 0.5 0.5 0.5 Isocyanate *10 60 60 60 60 60 60 60 YI value
Color migration 0.13 0.22 0.5 0.48 0.42 0.55 0.40 UV discoloration
10.22 15.13 26.9 19.51 19.52 18.43 21.33 NOx discoloration 13.09
15.11 19.03 20.55 33.31 30.84 37.93 Comparative Examples 1 2 3 4 5
6 7 8 9 10 Polyurethane Polyol *1 100 100 100 100 100 100 100 100
100 100 foam raw Antioxidant *2 material Antioxidant *11
compositions Antioxidant *3 0.30 0.30 0.30 0.30 0.30 0.30 (wt part)
Antioxidant *4 5.0 5.0 0.30 Ethanox 330 0.30 Cyanox 2246 0.30
Irganox 1010 0.30 Irganox 1076 0.30 UV absorbing agent *5 2.0 2.0
0.05 1.0 1.0 1.0 1.0 Water 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6
Amine catalyst *6 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Amine catalyst *7 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Foam stabilizer *8 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Tin
catalyst *9 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Isocyanate *10
60 60 60 60 60 60 60 60 60 60 YI value Color migration 35.21 33.36
29.31 31.06 30.55 32.07 0.45 0.49 0.48 0.52 UV discoloration 21.5
30.26 12.76 56.87 54.57 54.17 31.42 30.55 25.88 30.85 NOx
discoloration 32.47 20.22 14.05 60.23 58.94 57.12 48.23 45.11 39.99
50.23 *1 GP 3000 available from Dow Polyurethane Co., Ltd (no
antioxidant is added) *2 Phenolic antioxidant,
3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)
propioniloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxapyro [5,5]
undecane AO80, available from Asahi Denka Kogyo K.K. (molecular
weight of 741) *11 Phenolic antioxidant, 2,2'-thio-diethylene bis
[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate AO75, available from
Asahi Denka Kogyo K.K. (molecular weight of 642.9) *3 Phenolic
antioxidant, BHT, available from Asahi Denka Kogyo K.K. (molecular
weight of 220) *4 Phosphorus type antioxidant, Adeka 3010,
available from Asahi Denka Kogyo K.K. (molecular weight of 503) *5
Benzotriazole type UV absorbing agent, T-213, available from
Ciba-Geigy Ltd. *6 Triethylene diamine, DABCO-33LV, available from
Sankyo Airproducts Co., Ltd. *7 A133, available from Sankyo
Airproducts Co., Ltd. *8 L6202B, silicone oil available from Nippon
Unicar Co., Ltd. *9 U-28, available from Nittoh Chemical Industries
Ltd. *10 tolylene diisocyanate, T-80, available from Dow
Polyurethane Co., Ltd
[0050] Table 1 shows that the discoloration of the foam itself or
the color migration can be prevented according to the present
invention.
[0051] The preceding examples can be repeated with similar success
by substituting the generically or specifically described reactants
and/or operating conditions of this invention for those used in the
preceding examples.
[0052] As described above, according to the present invention there
is provided a soft polyurethane foam which is free from problems of
discoloration of the foam itself or color migration, and which is
useful for a pad material for clothing-related uses.
[0053] The foregoing is considered illustrative only of the
principles of the invention. Further, since numerous modifications
and changes will readily occur to those skilled in the art, it is
not desired to limit the invention to the exact construction and
operation shown and described. Accordingly, all suitable
modifications and equivalents may be resorted to that fall within
the scope of the invention and the appended claims.
* * * * *